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471.
Akihiro Makino Takeshi Kubota Chuntao Chang Masahiro Makabe Akihisa Inoue 《Journal of magnetism and magnetic materials》2008
Fe-based amorphous alloy ribbons are one of the major soft magnetic materials, because of their superior magnetic properties such as the relatively high saturation magnetization (Js) of 1.5–1.6 T and good magnetic softness. However, the preparation of the ordinary amorphous magnetic alloys requires cooling rates higher than 104 K/s due to the low glass-forming ability (GFA) and thus restricts the material outer shape. Recently, Fe-metalloid-based bulk metallic glasses (BMGs) containing glass-forming elements such as Al, Ga, Nb, Mo, Y and so forth have been developed. These alloys have high GFA, leading to the formation of BMG rod with diameters of mm-order. However, the glass-forming metal elements in BMGs result in a remarkable decrease in magnetization. Basically, Js depends on Fe content; hence, high Js requires high Fe content in the Fe-based amorphous alloys or BMGs. On the other hand, high GFA requires a large amount of glass-forming elements in the alloys, which results in lower Fe content. Therefore, in substances, the coexistence of high Js and high GFA is difficult. Since this matter should be immensely important from academia to industry in the material field, a great deal of effort has been devoted; however, it has remained unsolved for many years. In this paper, we present a novel Fe-rich FeSiBP BMG with high Js of 1.51 T comparable to the ordinary Fe–Si–B amorphous alloy now in practical use as well as with high GFA leading to a rod-shaped specimen of 2.5 mm in diameter, obtained by Cu-mold casting in air. 相似文献
472.
473.
X.Y. Gong H. Kan T. Makino K. Watanabe T. Iida H. Suzuki M. Aoyama T. Yamaguchi 《Crystal Research and Technology》2000,35(5):549-555
Mid‐infrared light emitting diodes (LED) in 3‐5μm wavelength range have been fabricated from InAs/InAsxP1‐x‐ySby/InAsx'P1‐x'‐y'Sby' composition graded layer and InAs/InAsSb multilayers. The heterostructures were grown by liquid phase epitaxy (LPE) between 600 and 520°C. An output power of 3.1 mW at 11K and of 10 μW at 300 K have been obtained under a peak current of 100 mA (50 % duty ratio) from InAsSb multilayers. Recombination mechanisms for these diodes were studied by temperature‐dependent emission spectra using Fourier transform infrared (FTIR) measurement system with double modulation. The output powers of the LEDs decrease rapidly at temperatures above 153 K suggesting that nonradiative and Auger recombinations are the main limitation of the device performance at high temperatures. 相似文献